KR20110119486A - Double-sided display device and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a double-sided display device including a plurality of first pixels formed on one surface and a plurality of second pixels formed on the other surface and displaying image information on both sides thereof, the first substrate having flexibility; A plurality of first transistors formed on the first substrate and respectively corresponding to the plurality of first pixels, and a plurality of second transistors formed on the first substrate and respectively corresponding to the plurality of second pixels. A transistor array substrate; A first cover substrate facing one surface of the transistor array substrate; A first display layer formed between the transistor array substrate and the first cover substrate corresponding to the plurality of first pixels; A second cover substrate facing the other surface of the transistor array substrate; And a second display layer formed between the transistor array substrate and the second cover substrate in correspondence with the plurality of second pixels.

Description

DOUBLE DISPLAY DEVICE AND MANUFACTURING METHOD OF THE SAME

The present invention relates to a double-sided display device and a manufacturing method thereof capable of displaying different images on both sides.

In recent years, as the information age has entered, the display field for visually expressing electrical information signals has been rapidly developed, and various flat panel display devices having excellent performance of thinning, light weight, and low power consumption have been developed. Flat Display Device has been developed to quickly replace the existing Cathode Ray Tube (CRT).

Specific examples of such a flat panel display include a liquid crystal display (LCD), an organic light emitting display (OLED), an electrophoretic display (EPD, Electric Paper Display), Plasma Display Panel Device (PDP), Field Emission Display Device (FED), Electroluminescence Display Device (ELD) and Electro-Wetting Display (EWD) Etc. can be mentioned. They commonly have a flat panel display panel that implements an image as an essential component. The flat panel panel has a configuration in which a pair of substrates are faced to each other with a layer of a unique light emitting material or polarizer therebetween. Among them, a liquid crystal display (LCD) displays an image by adjusting the light transmittance of the liquid crystal by using an electric field, and an organic light emitting display device is generated by recombination of electrons and holes. An image display is implemented by using an organic light emitting diode that generates light having a specific wavelength by energy from excitons.

In addition, an electrophoretic display device (EPD) is one of flat panel display devices used in an E-book, and is formed between two display panels on which field generating electrodes are formed, and between the two display panels. And a microcapsule comprising an electric ink, each having white and black color and having positively and negatively charged pigment particles. Such an electrophoretic display generates a potential difference across two electrodes by applying a voltage to two opposite electrodes, thereby moving black and white charged pigment particles to electrodes having opposite polarities, respectively, to display an image. Therefore, the electrophoretic display has a high reflectivity and contrast ratio, and unlike a liquid crystal display, there is no dependence on the viewing angle so that an image can be displayed with a comfortable feeling like paper. It has a bistable characteristic of black and white, which can maintain an image without applying continuous voltage, and thus has a small power consumption.

On the other hand, the flat panel display device has the advantages of thin thickness and low power consumption, and can be manufactured as a double-sided display device displaying different image information on both sides, and the double-sided display device is a display device that replaces an advertisement board or a guide sign or a screen. As a result, the demand is increasing.

The conventional double-sided display device is formed by attaching a first panel for displaying an image in a first direction and a second panel for displaying an image in a second direction so that the rear surfaces of the surfaces on which the image is displayed face each other. Here, each of the first panel and the second panel includes a transistor array substrate having a plurality of switching transistors defining a plurality of pixels and controlling the luminance of the plurality of pixels, a cover substrate facing the transistor array substrate, and a transistor. It comprises a light emitting layer or a polarizing layer formed between the array substrate and the first cover substrate.

As described above, the conventional double-sided display device includes both the transistor array substrate of the first panel and the transistor array substrate of the second panel, and thus, it is difficult to reduce the thickness and weight.

In addition, since the manufacturing process is performed through a process including preparing a first panel and a second panel, and attaching the first panel and the second panel, the manufacturing process is complicated, yield improvement is difficult, and manufacturing cost is increased. There is a problem. In addition, since the adhesive layer must be provided between the first panel and the second panel, there is a problem in that the life of the double-sided display device depends on the adhesive holding period of the adhesive layer. In this case, since the first panel and the second panel should be attached flat, the transistor array substrate of each of the first panel and the second panel is formed using a rigid substrate to facilitate the attachment process of the first panel and the second panel. do. Accordingly, the conventional double-sided display device cannot be manufactured as a flexible display device, and thus has a problem of low practicality.

The present invention can display different image information on both sides including a plurality of first pixels formed on one surface and a plurality of second pixels formed on the other surface, and each of the plurality of first pixels and the plurality of second pixels A plurality of first transistors, a plurality of second transistors, a plurality of first pixel electrodes, and a plurality of second pixel electrodes for controlling luminance may be formed on a single substrate, and thus may be formed to have a thinner thickness and lighter weight than the prior art. The present invention provides a double-sided display device and a method of manufacturing the same, which can remove the adhesive layer and facilitate the manufacturing process.

In order to solve the above problems, the present invention provides a double-sided display device for displaying image information on both sides with a first display unit on one surface and a second display unit on the other surface, the first substrate; A plurality of first unit pixels formed on one surface of the first substrate and constituting the first display unit; A plurality of second unit pixels formed on the other surface of the first substrate and constituting the second display unit; A plurality of first switching elements formed on the first substrate and respectively corresponding to the plurality of first unit pixels, and formed on the same surface as the plurality of first switching elements and respectively corresponding to the plurality of second unit pixels. An array substrate including a plurality of second switching elements; A first display layer formed on the first display unit; It provides a double-side display device comprising a second display layer formed on the second display unit.

In addition, the present invention provides a method of manufacturing a double-side display device for displaying image information on both surfaces, including a plurality of first pixels formed on one surface and a plurality of second pixels formed on the other surface, the method comprising: Forming a plurality of first pixel electrodes respectively corresponding to the plurality of second pixels; Forming a flexible first substrate on a portion of the transfer substrate including the plurality of first pixel electrodes; Providing a transistor array substrate including the first substrate, a plurality of first transistors respectively corresponding to the plurality of first pixels, and a plurality of second transistors respectively corresponding to the plurality of second pixels; Providing a first display layer corresponding to the plurality of first pixels on one surface of the transistor array substrate; Removing the transfer substrate from the transistor array substrate by separating the first substrate and the transfer substrate; And providing a second display layer corresponding to the plurality of second pixels on the other surface of the transistor array substrate.

As described above, the double-sided display device according to the exemplary embodiment of the present invention includes a plurality of first pixels formed on one surface and a plurality of second pixels formed on the other surface, and the plurality of first pixels and the plurality of first pixels. Different image information is displayed on both surfaces, including a plurality of first transistors and a plurality of second transistors respectively controlling the second pixel. In this case, the plurality of first transistors and the plurality of second transistors are formed on one surface of one substrate, and the plurality of first pixel electrodes applying pixel voltages corresponding to each of the plurality of first pixels are disposed on the upper surface of the substrate. And a plurality of second pixel electrodes applying a pixel voltage corresponding to each of the plurality of second pixels is formed on the rear surface of the substrate. That is, transistor array substrates corresponding to both the plurality of first pixels and the plurality of second pixels may be integrally formed. Therefore, compared with the prior art having a structure in which two transistor array substrates corresponding to each of a plurality of first pixels and a plurality of second pixels are bonded together, at least one substrate can be removed, thereby reducing thickness and weight. Can be. Further, since a plurality of first transistors and a plurality of second transistors can be simultaneously formed on one substrate, and two substrates do not need to be attached, the manufacturing process becomes easier, the manufacturing cost is reduced, and the yield is improved. Can be. In addition, since the transistor array substrate may be formed using one flexible substrate, the transistor array substrate may be manufactured as a flexible display device, thereby improving practicality.

1 is a cross-sectional view illustrating a double-sided display device according to an exemplary embodiment of the present invention.
FIG. 2 is a cross-sectional view illustrating the transistor array substrate illustrated in FIG. 1.
3A and 3B are equivalent circuit diagrams of the transistor array substrate shown in FIG.
4 is a flowchart illustrating a manufacturing method of a double-sided display device according to an exemplary embodiment of the present invention.
5A and 5B are process diagrams illustrating the steps of forming the first substrate illustrated in FIG. 4.
5C is a graph showing the characteristics of a transistor formed using a substrate made of a sheet-like plastic material.
5D is a graph showing the characteristics of a transistor formed using a substrate formed by coating polyimide.
FIG. 6 is a flowchart illustrating detailed steps of preparing a transistor array substrate illustrated in FIG. 4.
7A to 7B are process diagrams illustrating the steps of preparing the transistor array substrate shown in FIG. 6.
8 is a cross-sectional view illustrating a double-side display device according to a first embodiment of the present invention.
9A and 9B are process diagrams illustrating a process of manufacturing a double-sided display device according to a first embodiment of the present invention.
10 is a cross-sectional view illustrating a double-side display device according to a second embodiment of the present invention.
11A through 11D are process diagrams illustrating a process of manufacturing a double-side display device according to a second exemplary embodiment of the present invention.
12 is a cross-sectional view illustrating a double-sided display device according to a third exemplary embodiment of the present invention.
13A to 13D are process diagrams illustrating a process of manufacturing a double-sided display device according to a third exemplary embodiment of the present invention.
14 is a cross-sectional view illustrating a double-sided display device according to a fourth exemplary embodiment of the present invention.
15A to 15D are process diagrams illustrating a process of manufacturing a double-sided display device according to a fourth exemplary embodiment of the present invention.

Hereinafter, a double-sided display device and a manufacturing method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, a double-sided display device according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1 to 3B.

1 is a cross-sectional view illustrating a double-sided display device according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of the transistor array substrate illustrated in FIG. 1. 3A and 3B are equivalent circuit diagrams of the transistor array substrate shown in FIG.

A double-sided display device according to an embodiment of the present invention is a device for displaying image information on both sides by including a first display unit on one surface and a second display unit on the other surface, and a first display unit disposed between the first display unit and the second display unit. A plurality of first unit pixels (hereinafter, referred to as "a plurality of first pixels") formed on one side of the substrate and the first substrate to form the first display unit, and the second display unit formed on the other side of the first substrate. A plurality of second unit pixels (hereinafter, referred to as "a plurality of second pixels") to constitute; a plurality of first switching elements formed on the first substrate and respectively corresponding to the plurality of first pixels; An array substrate including a plurality of second switching elements formed on the same surface as the plurality of first switching elements and corresponding to the plurality of second pixels, and a first display layer and the second formed on the first display unit. The second display layer formed on the display unit It is characterized by including. The first and second display units may include a first cover substrate and a second cover substrate respectively opposite to both surfaces of the array substrate. In addition, the first substrate is made of a flexible plastic material having heat resistance, and in particular, made of polyimide.

Each of the plurality of first switching elements and the plurality of second switching elements may include a thin film transistor including a gate electrode, a gate insulating layer, a semiconductor layer, a source electrode, and a drain electrode. In this case, since the array substrate includes a plurality of first switching elements and a plurality of second switching elements each formed of a thin film transistor, the array substrate is also referred to as a "transistor array substrate". The array substrate may include a protective layer covering a plurality of first switching elements and a plurality of second switching elements to protect a surface, a plurality of first pixel electrodes connected to the plurality of first switching elements, and the plurality of first switching elements, respectively. The apparatus further includes a plurality of second pixel electrodes respectively connected to the second switching elements. Here, the plurality of first pixel electrodes are formed in the protective layer, and are connected to the plurality of first switching elements, respectively, through the plurality of first contact holes respectively formed in the protective layer corresponding to the plurality of first pixels. The plurality of second pixel electrodes are formed on the rear surface of the first substrate, and are connected to the plurality of second switching elements through a plurality of first contact holes respectively formed corresponding to the plurality of second pixels.

The first display layer may include an electron ink layer and a first common electrode, and the second display layer may include an electron ink layer and a second common electrode. Alternatively, the first display layer may include an organic light emitting layer, and the second display layer may include an electron ink layer. Alternatively, the first display layer may include a liquid crystal layer, and the second display layer may include an electron ink layer. Here, the organic light emitting layer is at least one organic layer formed corresponding to each of the plurality of first pixels.

Referring to the drawings, a double-sided display device according to an embodiment of the present invention will be described in more detail.

The double-sided display device according to the exemplary embodiment of the present invention includes a plurality of first pixels formed on one surface corresponding to the first display part and a plurality of second pixels formed on the other surface corresponding to the second display part, Displays different image information. As shown in FIG. 1, the double-sided display device 100 according to the exemplary embodiment of the present invention includes a plurality of first transistors corresponding to the plurality of first pixels and a plurality of second pixels respectively corresponding to the plurality of first pixels. A transistor array substrate 110 including a second transistor, a first cover substrate 120 facing one surface of the transistor array substrate 110, and a transistor array substrate 110 and a first cover corresponding to a plurality of first pixels. The transistor array substrate 110 corresponds to the first display layer 130 formed between the substrate 120, the second cover substrate 140 facing the other surface of the transistor array substrate 110, and the plurality of second pixels. And a second display layer 150 formed between the second cover substrate 140 and the second cover substrate 140.

Here, as illustrated in FIG. 2, the transistor array substrate 110 includes a flexible first substrate 111, a plurality of first transistors TFT1 and a plurality of first transistors formed on the first substrate 111. The plurality of first pixel electrodes PX1 connected to the second transistor TFT2, the plurality of first transistors TFT1, and the plurality of second pixel electrodes PX2 connected to the plurality of second transistors TFT2, respectively. It is made to include. For reference, FIG. 2 is a cross-sectional view of a portion of the transistor array substrate 110 including one first pixel and one second pixel.

The first substrate 111 may be soluble in a predetermined solvent, and may be patterned by wet etching, dry etching, or laser, and may be provided in each of the first transistor TFT1 and the second transistor TFT2. It is made of a plastic material having heat resistance to the heat of the process temperature applied during the deposition process of the semiconductor layer. Such plastic materials include polyimide. Particularly, when the first substrate 111 is made of polyimide, the first substrate 111 may be formed by coating the transfer substrate in a state dissolved in a predetermined solvent, thereby removing an adhesive layer for adhering to the transfer substrate. It is possible to form a contact hole penetrating through the first substrate 111 as needed, and has heat resistance to a temperature of 350 degrees Celsius, which is a process temperature for depositing a semiconductor layer, so that it is high in the deposition process of the semiconductor layer. The deformation of the form by the temperature of the heat can be prevented.

Each of the plurality of first transistors TFT1 and the plurality of second transistors TFT2 may be formed on the first substrate 111 including the gate electrode G and the gate electrode G formed on the first substrate 111. The gate insulating layer 112 formed on the entire surface, the semiconductor layer 113 formed at least partially overlapping with the gate electrode G on the gate insulating layer 112, and the gate electrode G on the semiconductor layer 113. It comprises a source electrode (S1, S2) and drain electrodes (D1, D2) formed to overlap each of both sides of. In this case, the source electrodes S1 and S2 of the plurality of first transistors TFT1 and the plurality of second transistors TFT2, that is, the plurality of first transistors TFT1 and the plurality of second transistors TFT2, respectively. ) And a protective layer 114 for physically or electrically protecting the plurality of first transistors TFT1 and the plurality of second transistors TFT2 on the entire surface of the gate insulating layer 112 including the drain electrodes D1 and D2. ) Is formed.

The plurality of first pixel electrodes PX1 are formed through the plurality of first contact holes 115 formed on the passivation layer 114 to correspond to partial regions of the plurality of first transistors TFT1, respectively. It is connected to the transistor TFT1, respectively. In this case, the plurality of first contact holes 115 are formed in the passivation layer 114 to correspond to a portion of the drain electrode D1 of each of the plurality of first transistors TFT1. The first pixel electrode PX1 is formed on the passivation layer 114 to correspond to the pixel regions of the plurality of first pixels, respectively, and the plurality of first transistors TFT1 through the plurality of first contact holes 115. Are connected to the respective drain electrodes D1.

The plurality of second pixel electrodes PX2 is disposed on the rear surface of the first substrate 111 on which the plurality of first transistors TFT1, the plurality of second transistors TFT2, and the plurality of first pixel electrodes PX1 are not formed. And a plurality of second transistors TFT2 through the plurality of second contact holes 116 formed in the first substrate 111 and the gate insulating layer 112. In this case, the plurality of second contact holes 116 may be formed in the gate insulating layer 112 and the first substrate 111 to correspond to the partial regions of the plurality of second pixel electrodes PX2, respectively, or the second transistor ( The semiconductor layer 113, the gate insulating layer 112, and the first substrate 111 of the TFT2 are formed to correspond to a part of the plurality of second pixel electrodes PX2. That is, the plurality of second contact holes 116 are formed to penetrate at least the gate insulating layer 112 and the first substrate 111 to expose some regions of the plurality of second pixel electrodes PX2. The drain electrodes D2 of the plurality of second transistors TFT2 are respectively connected to the plurality of second pixel electrodes PX2 through the plurality of second contact holes 116.

Meanwhile, the plurality of first transistors TFT1 and the plurality of second transistors TFT2 are driven by the first transistor driver 200 and the second transistor driver 300, respectively, as shown in FIG. 3A. That is, the plurality of first transistors TFT1 are turned on / off by a gate signal applied from the first gate driver 210 connected to the transistor array substrate 110, and the first source / drain driver is turned on when the first transistor TFT1 is turned on. The data signal of 220 is applied to the first pixel electrode PX1. The plurality of second transistors TFT2 are turned on / off by a gate signal applied from the second gate driver 310 connected to the transistor array substrate 110, and the second source / drain driver is turned on. The data signal of 320 is applied to the second pixel electrode PX2.

Alternatively, when the plurality of first transistors TFT1 and the plurality of second transistors TFT2 have threshold voltages having the same voltage level, as illustrated in FIG. 3B, the common gate driver 400 may be shared to share the common gate. It may be turned on / off at the same time by the gate signal applied from the driver 400. However, even in this case, the plurality of first transistors TFT1 receives a data signal from the first source / drain driver 220, and the plurality of second transistors TFT2 may be supplied from the second source / drain driver 320. The data signal is applied.

The double-sided display device 100 according to an exemplary embodiment of the present invention includes a first display layer 130 corresponding to a plurality of first pixels and a second display layer 150 corresponding to a plurality of second pixels. . Here, the second display layer 150 is composed of an electron ink layer including microcapsules formed in a form in which two kinds of pigment particles charged with opposite polarities and reflective properties and a solvent in which the pigment particles are dispersed are sealed. The first display layer 130 may include an electron ink layer including two types of pigment particles charged with opposite polarities and reflecting polarity, and microcapsules formed by sealing a solvent in which the pigment particles are dispersed. The liquid crystal layer may include at least one organic layer emitting light by the injected carrier, or a liquid crystal layer including a liquid crystal cell that selectively scatters light according to an electric field. The first cover substrate 120, the first display layer 130, the second cover substrate 140, and the second display layer 150 will be described in detail for each embodiment below.

As described above, the double-sided display device 100 according to the exemplary embodiment of the present invention uses a plurality of first transistors TFT1 and a plurality of first transistors corresponding to the plurality of first pixels using one first substrate 111. A plurality of second transistors TFT2 and a plurality of second pixel electrodes PX2 corresponding to the pixel electrode PX1 and the plurality of second pixels are formed. As a result, compared with the prior art having a structure in which two transistor array substrates respectively corresponding to the plurality of first pixels and the plurality of second pixels are attached, they may be formed with a thin thickness and a light weight. Since it is not necessary to attach two substrates, it is possible to prevent the reliability of the device from being weakened by the adhesive layer known to be low in durability and heat resistance, and to prevent a decrease in life. In addition, since it is not necessary to form the transistor array substrate by using a rigid substrate, it can be manufactured with a flexible display device, and the practicality can be improved. In addition, since the plurality of first transistors TFT1 and the plurality of second transistors TFT2 may be formed at the same time, the manufacturing process may be easier, and thus the yield may be improved.

Hereinafter, a method of manufacturing a double-side display device according to an exemplary embodiment of the present invention will be described with reference to FIGS. 4 to 7.

4 is a flowchart illustrating a manufacturing method of a double-sided display device according to an exemplary embodiment of the present invention. 5A and 5B are process diagrams illustrating the steps of forming the first substrate illustrated in FIG. 4. 5C is a graph showing the characteristics of a transistor formed using a substrate made of a sheet-like plastic material, and FIG. 5D is a graph showing the characteristics of a transistor formed using a substrate formed by coating a polyimide. FIG. 6 is a flowchart illustrating detailed steps of preparing a transistor array substrate illustrated in FIG. 4. 7A and 7B are process diagrams illustrating the steps of preparing the transistor array substrate shown in FIG. 6.

In the method of manufacturing the double-sided display device according to the exemplary embodiment of the present invention, as illustrated in FIG. 4, a plurality of second pixel electrodes PX2 corresponding to the plurality of second pixels are formed on the rigid and flat transfer substrate. Forming a first substrate 111 having flexibility in a portion of a transfer substrate including a plurality of second pixel electrodes PX2 (S110), a first substrate 111, and a plurality of first substrates. (S120) preparing a transistor array substrate 110 including a plurality of first transistors TFT1 corresponding to pixels and a plurality of second transistors TFT2 respectively corresponding to a plurality of second pixels (S120). Preparing a first display layer 130 corresponding to a plurality of first pixels on one surface of the substrate 110 (S130), separating the first substrate 111 and the transfer substrate from the transistor array substrate 110. Removing the transfer substrate (S140) and the other of the transistor array substrate 110 And a step (S150) of providing the second display layer 150 corresponding to a plurality of second pixels on a side.

In the double-sided display device according to the exemplary embodiment of the present invention, the plurality of second pixel electrodes PX2 respectively corresponding to the plurality of second pixels is formed on the rear surface of the first substrate 111. Accordingly, before forming the first substrate (S110), a plurality of second pixel electrodes PX2 corresponding to the plurality of second pixels are formed on the transfer substrate (S100).

Next, in step S110 of forming the first substrate 111, the first substrate 111 is formed of a plastic material on a portion of the transfer substrate including the plurality of second pixel electrodes PX2. In this case, the first substrate 111 may be provided in the form of a sheet such as plastic such as stainless steel (STS), PEN, PS, and PC, and may be attached to the transfer substrate through an adhesive layer to form the first substrate 111. have. Alternatively, as shown in FIG. 5A, the plastic material may be patterned in a solid state, and the plastic material may be transferred on a CSub in a state in which a plastic material having heat resistance to heat at a process temperature during the deposition process of the semiconductor layer is dissolved in a predetermined solvent. After dropping in, as shown in FIG. 5B, it is also possible to form the first substrate 111 attached to the transfer substrate CSub by flatly and thinly spreading the plastic material. In this case, the first substrate 111 may be patterned by wet etching, dry etching, or laser in a solid state, and the deposition process of the semiconductor layer provided in each of the first transistor TFT1 and the second transistor TFT2. It may be formed of polyimide having heat resistance to heat of the process temperature applied to the city and having solubility in a predetermined solvent.

For example, since a substrate made of a sheet-shaped plastic material has a heat resistance temperature of about 200 degrees Celsius, it may be easily deformed by heat of 350 degrees Celsius, which is a process temperature for depositing a semiconductor layer. Accordingly, when the transistor is formed using a substrate made of a sheet-like plastic material, since the semiconductor layer is to be deposited at a temperature of 200 degrees Celsius or less, as shown in FIG. 5C, an error in the threshold voltage Vth may occur. By appearing at 4V or more, there is a problem that the reliability of the transistor is lowered. On the other hand, since the substrate made of a polyimide coatable in a predetermined solvent has a heat resistance temperature of 350 degrees Celsius or more, the shape is not changed by heat of 350 degrees Celsius, which is a process temperature for depositing a semiconductor layer. Accordingly, when the transistor is formed using a substrate made of polyimide, the semiconductor layer may be deposited at a temperature of 350 degrees Celsius, and as shown in FIG. 5D, an error of the threshold voltage Vth is 2V or less. As a result, the reliability of the transistor is higher than that of the transistor shown in Fig. 5C. Accordingly, in the case of using the first substrate 111 made of polyimide, the transistor array substrate may be formed of a flexible substrate, but the problem of deterioration of the reliability of the transistor does not occur. In addition, since a substrate made of a sheet-like plastic material can be attached to the transfer substrate only through a separate adhesive layer, the manufacturing method becomes complicated, and deformation of the adhesive layer may occur due to heat resistance of the adhesive layer. There is a problem that a high process error occurs. On the other hand, the substrate made of polyimide can be combined with the transfer substrate in a coating manner, so that the substrate is attached to the transfer substrate at the same time as the formation of the substrate, so that the manufacturing method becomes easier, and there is no need to include an adhesive layer. Form deformation due to the adhesive layer can be prevented, the yield can be improved, there is an advantage that can reduce the process error.

Next, a method of manufacturing the double-sided display device according to the exemplary embodiment of the present invention shown in FIG. 4 will be described.

By forming the plurality of second pixel electrodes PX2 (S100) and forming the first substrate 111 (S110), as illustrated in FIG. 7A, the plurality of second pixel electrodes PX2. ) Is formed on the transfer substrate CSub, and the first substrate 111 is formed to cover the plurality of second pixel electrodes PX2 on the plurality of second pixel electrodes PX2.

As illustrated in FIG. 6, the preparing of the transistor array substrate (S120) corresponds to each of the plurality of first transistors TFT1 and the plurality of second transistors TFT2, and the gates are formed on the first substrate 111. Forming an electrode G (S121), forming a gate insulating layer 112 on the entire surface of the first substrate 111 including the gate electrode G (S122), and a plurality of first transistors TFT1. And corresponding to each of the plurality of second transistors TFT2, forming a semiconductor layer 113 on the gate insulating layer 122 at least partially overlapping the gate electrode G (S123) and the first substrate ( Forming a plurality of second contact holes 116 corresponding to partial regions of the plurality of second pixel electrodes PX2 in the 111 and the gate insulating layer 112 (S124), and the plurality of first transistors TFT1. ) And source electrodes S1 and S2 respectively overlapping both sides of the gate electrode G on the semiconductor layer 113, corresponding to each of the plurality of second transistors TFT2. ) And forming the drain electrodes D1 and D2 (S125), and protecting the entire surface of the gate insulating layer 112 including the semiconductor layer 113, the source electrodes S1 and S2, and the drain electrodes D1 and D2. Forming a layer 114 (S126), forming a plurality of first contact holes 115 corresponding to partial regions of the plurality of first transistors TFT1 in the protective layer 114 (S127), and And forming a plurality of first pixel electrodes PX1 connected to the plurality of first transistors TFT1 on the protective layer 114, respectively (S128). In this case, in the forming of the plurality of second contact holes 116, at least the gate insulating layer 112 and the first substrate corresponding to a partial region of the second pixel electrode PX2, as illustrated in FIG. 7B. A second contact hole 116 penetrating the 111 is formed. In the forming of the source electrodes S1 and S2 and the drain electrodes D1 and D2, the drain electrodes D2 of the plurality of second transistors TFT2 are formed through the plurality of second contact holes 116. Are respectively connected to the second pixel electrodes PX2.

2 and 7B, the plurality of second contact holes 116 penetrate the first substrate 111, the gate insulating layer 112, and the semiconductor layer 113 of the second transistor TFT. Although illustrated as having, the shape of the drain electrode D2 may be formed so as to penetrate only the first substrate 111 and the gate insulating layer 112.

2 and 7B, the drain electrode D1 of the first transistor TFT1 is connected to the first pixel electrode PX1 through the first contact hole 115 and the drain of the second transistor TFT2 is formed. Although the electrode D2 is illustrated as being connected to the second pixel electrode PX2, unlike the drain electrodes D1 and D2 according to device characteristics of the first transistor TFT1 and the second transistor TFT2, Source electrodes S1 and S2 of each of the first transistor TFT1 and the second transistor TFT2 may be connected to the first pixel electrode PX1 and the second pixel electrode PX2, respectively.

Next, a first display layer corresponding to the plurality of first pixels is formed on one surface of the transistor array substrate 110 (S130). In this case, the first cover substrate 120 may be further provided to face one surface of the transistor array substrate 110.

Then, the first substrate 111 and the transfer substrate CSub are separated to remove the transfer substrate CSub from the transistor array substrate 110 provided with the first cover substrate and the first display layer (S140). At this time, the removal of the transfer substrate CSub may be performed by applying a high temperature heat through a laser by using a difference in thermal expansion coefficient, using an etching method such as UV or dry or wet method, or using a mechanical method by physical force. Can be.

In operation S150, a second display layer corresponding to the plurality of second pixels is provided on the other surface of the transistor. In this case, the second cover substrate 140 facing the other surface of the transistor array substrate 110 may be further provided.

Hereinafter, a double-sided display device according to each embodiment of the present invention will be described.

8 is a cross-sectional view illustrating a double-sided display device according to a first embodiment of the present invention, and FIGS. 9A and 9B are flowcharts illustrating a process of manufacturing the double-sided display device according to the first embodiment of the present invention.

As shown in FIG. 8, the double-sided display device according to the first embodiment includes a plurality of first pixels driven on one surface by an electrophoretic display method, and a plurality of second pixels driven on another surface by an electrophoretic display method. It is made, including.

That is, the double-sided display device according to the first embodiment includes a transistor array substrate 110a for controlling luminance of each of a plurality of first pixels and a plurality of second pixels, and a first cover substrate corresponding to the plurality of first pixels. And a second cover substrate 140 and a second display layer 150 corresponding to the first display layer 130a and the plurality of second pixels. Here, each of the first display layer 130a and the second display layer 150 is formed of an electron ink layer including microcapsules formed by sealing a solvent in which two kinds of pigment particles having opposite polarities are dispersed. . In this case, the first cover substrate 120a and the second cover substrate 140 may be removed.

Specifically, according to the first embodiment, the transistor array substrate 110a includes a first substrate 111, a plurality of first transistors TFT1 and a plurality of second transistors TFT2 formed on the first substrate 111. ), A plurality of first pixel electrodes PX1 connected to the plurality of first transistors TFT1, a plurality of second pixel electrodes PX2 connected to the plurality of second transistors TFT2, and a plurality of firsts, respectively. And a passivation layer 114a formed on the transistor TFT1 and the plurality of second transistors TFT2 and an upper passivation layer 114b formed flat on the passivation layer 114a. Here, in the transistor array substrate 110a according to the first embodiment, the upper protection layer 114b formed on the protection layer 114a and the plurality of first pixel electrodes PX1 formed on the upper protection layer 114b. Except), the description thereof is the same as the description of the transistor array substrate 110 illustrated in FIG. 2, and thus descriptions thereof will be omitted.

The upper passivation layer 114b is formed on the passivation layer 114a to correspond to the pixel region of each of the plurality of first pixels including the tops of the plurality of second transistors TFT2, and thus, the plurality of first pixel electrodes PX1. It may be formed adjacent to the first display layer 130a. The plurality of first pixel electrodes PX1 are formed on the upper passivation layer 114b, and the plurality of first pixel electrodes PX1 are formed on the passivation layer 114a and the upper passivation layer 114b to correspond to partial regions of the plurality of first transistors TFT1. The first contact holes 115 are connected to the plurality of first transistors TFT1, respectively.

The first cover substrate 120a is formed of a material having transparency and flexibility, so that the second substrate 121 facing the one surface of the transistor array substrate 110a and the second substrate 121 facing the transistor array substrate 110a. ) Includes a first common electrode 122 formed on one surface of the second pixel to correspond to the plurality of first pixels.

The first display layer 130a includes an electron ink layer including a plurality of microcapsules spread therein and a binder made of a polymer filled between the plurality of microcapsules. In this case, each microcapsule is formed in a sealed form in which two kinds of pigment particles having polarities opposite to each other are dispersed. For example, the microcapsules are formed in a spherical shape having a diameter of about 40 μm, and therein, a solvent made of IPA (isopropyl alcohol) or the like and two kinds of pigment particles dispersed in the solvent are sealed. At this time, one of the two kinds of pigment particles is a titanium oxide-based white pigment particles formed of nano size and having a (-) polarity, the other is carbon-based black pigment particles formed of a nano size and having a (+) polarity Can be. The first display layer 130a is formed on the first common electrode 122 in the form of a film, and the first display layer 130a and the first cover substrate 120a are integrally formed. In addition, the first display layer 130a is disposed between the first cover substrate 120a and the transistor array substrate 110a such that the first display layer 130a is disposed on the transistor array substrate 110a through the first adhesive layer AD1. It is attached to one side of).

As such, the first display layer 130a including the electron ink layer has white pigment particles having a negative polarity when a voltage having a higher level than that of the first common electrode 122 is applied to the first pixel electrode PX1. Is positioned adjacent to the first pixel electrode PX1, and black pigment particles having positive polarity are positioned adjacent to the first common electrode 122 arranged in the direction in which light is emitted, thereby reducing the luminance of the pixel. To indicate. On the contrary, when a voltage having a lower level than that of the first common electrode 122 is applied to the first pixel electrode PX1, black pigment particles having a positive polarity may be formed in the first display layer 130a. Located adjacent to the (PX1) side, the white pigment particles having the (-) polarity are located adjacent to the first common electrode 122 side arranged in the direction in which light is emitted, thereby causing the pixel to exhibit high luminance.

The second cover substrate 140 is formed of a material having transparency and flexibility, and includes a third substrate 141 facing the other surface of the transistor array substrate 110a and a substrate facing the transistor array substrate 110a. The second common electrode 142 is formed on one surface of the third substrate 141 to correspond to the plurality of second pixels.

Similar to the first display layer 130a, the second display layer 150 includes an electron ink layer including a plurality of microcapsules spread therein and a binder made of a polymer filled between the microcapsules. In this case, each microcapsule is formed in a sealed form in which two kinds of pigment particles having polarities opposite to each other are dispersed. The second display layer 150 is formed in a film form on the second common electrode 142, and the second display layer 150 and the second cover substrate 140 are integrally formed. In addition, the second display layer 150 may be disposed between the second cover substrate 140 and the transistor array substrate 110a such that the second display layer 150 is disposed on the transistor array substrate 110a through the second adhesive layer AD2. Is attached to the other side of the

According to the method of manufacturing the double-sided display device according to the first embodiment configured as described above, before forming the plurality of first contact holes 115 (S127), the upper protective layer 114b is disposed on the protective layer 114a. 6, except that the first pixel electrode PX1 is formed on the upper passivation layer 114b in the step S128 of forming the first pixel electrode PX1. The same method as the manufacturing method of the double-sided display device shown in FIG.

In addition, according to the first exemplary embodiment, in the preparing of the first cover substrate 120a and the first display layer 130a of FIG. 4 (S130), the plurality of first pixels may be disposed on the second substrate 121. Forming a first common electrode 122 corresponding to the first cover substrate 120a, preparing a first display layer 130a on the second common electrode 121, and forming a transistor array substrate ( Attaching the first display layer 130a to one surface of 110a). At this time, in the step of attaching the first display layer 130a to one surface of the transistor array substrate 110a, as shown in FIG. 9A, the first display layer 130a is formed of the first cover substrate 120a and the transistor array. The first display layer 130a and the transistor array substrate 110a are attached to each other using the adhesive layer AD1 formed on the first display layer 130a while being aligned to be positioned between the substrates 110a. In addition, in the preparing of the second cover substrate 140 and the second display layer 150 in FIG. 4 (S150), the preparing of the first cover substrate 120a and the first display layer 130a may be performed ( As in S130, forming the second cover substrate 140 by forming the second common electrode 142 corresponding to the plurality of second pixels on the third substrate 141, and the second common electrode 121. Forming a second display layer 150 on the substrate) and attaching the second display layer 150 to the other surface of the transistor array substrate 110a. At this time, in the step of attaching the second display layer 150 to the other surface of the transistor array substrate 110a, as shown in FIG. 9B, the second display layer 150 is the second cover substrate 140 and the transistor. The second display layer 140 and the transistor array substrate 110a are attached to each other using the adhesive layer AD2 formed on the second display layer 150 while being aligned to be positioned between the array substrates 110a.

In the double-side display device according to the first exemplary embodiment, even if two transistor arrays corresponding to the plurality of first pixels and the plurality of second pixels are disposed on one surface of the transistor array substrate 110a, the first display layer 130a may be used. ) And the microcapsule provided as the second display layer 150 are disposed on the upper surface of the transistor array substrate 110a, so that the reduction of the aperture ratio does not occur, and thus the image quality of both surfaces is not reduced. However, the double-sided display device according to the first embodiment is driven only by an electrophoretic display method of controlling only a turn-on / turn-off state of a pixel, and thus it is difficult to display a color image unless a separate color filter is provided.

Accordingly, according to the second to fourth embodiments of the present invention, the plurality of first pixels are driven by an organic light emitting display method using an organic light emitting diode or a liquid crystal display method using a liquid crystal cell so as to display a color image. do.

10 is a cross-sectional view illustrating a double-sided display device according to a second exemplary embodiment of the present invention, and FIGS. 11A to 11D are process diagrams illustrating a process of manufacturing the double-sided display device according to the second exemplary embodiment of the present invention.

As shown in FIG. 10, the double-sided display device according to the second exemplary embodiment of the present invention includes a plurality of first pixels driven on an organic light emitting display method on one surface thereof, and a plurality of first pixels driven on an electrophoretic display method on the other surface thereof. It comprises a second pixel of.

That is, the double-sided display device according to the second embodiment includes a transistor array substrate 110b for controlling the luminance of each of the plurality of first pixels and the plurality of second pixels, and a first cover substrate corresponding to the plurality of first pixels. 120b), the first display layer 130b, and the second cover substrate 140 and the second display layer 150 corresponding to the plurality of second pixels. Here, the first display layer 130b includes at least one organic layer 131 formed corresponding to each of the plurality of first pixels and a bank 132 formed corresponding to a boundary of each of the plurality of first pixels. . The second display layer 150, like the double-sided display device according to the first embodiment, includes an electronic ink including microcapsules formed in a form in which a solvent in which two kinds of pigment particles having opposite polarities are dispersed is sealed. Consists of layers.

The transistor array substrate 110b according to the second embodiment may include a first substrate 111, a plurality of first transistors TFT1, a plurality of second transistors TFT2, and a plurality of formed on the first substrate 111. A plurality of first pixel electrodes PX1 connected to the first transistor TFT1 of the plurality of pixels, a plurality of second pixel electrodes PX2 connected to the plurality of second transistors TFT2, and a plurality of first transistors TFT1 respectively; ) And a passivation layer 114 formed on the plurality of second transistors TFT2, and are the same as the description of the transistor array substrate 110 illustrated in FIG. 2. Let's do it.

According to the second embodiment, the first cover substrate 120b includes a second substrate 121 and a first common electrode 122 corresponding to the plurality of first pixels. The first display layer 130b includes at least one organic layer 131 corresponding to each of the plurality of first pixels on the transistor array substrate 110b. In this case, the organic layer 131 corresponding to each of the plurality of first pixels reacts with the carrier injected through the first pixel electrode PX1 and the first common electrode 122 to generate light of a specific wavelength region. That is, the first common electrode 122, the organic material 131, and the first pixel electrode PX1 form an organic light emitting diode including a cathode, an organic layer, and an anode electrode. In this case, the organic layer may include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and an electron injection layer. In addition, the organic layer 131 uses a principle that, when a current is injected, the organic molecules enter an excited state and then return to the original ground state to emit extra energy as light. The luminance of each of the first pixels is displayed.

In addition, according to the second embodiment, the second cover substrate 140 includes a third substrate 141 and a second common electrode 142 corresponding to the plurality of second pixels. In addition, the second display layer 150 includes a plurality of microcapsules spread therein and an electron ink layer including a binder made of a polymer filled between the plurality of microcapsules. Each microcapsule has polarities opposite to each other. It consists of the form which sealed the solvent in which the two types of pigment particle which it has disperse | distributed. Here, the second cover substrate 140 and the second display layer 150 according to the second embodiment may include the second cover substrate 140 and the second display layer 150 according to the first embodiment shown in FIG. 8. Since the description is the same as), duplicate descriptions will be omitted below.

According to the method of manufacturing the double-sided display device according to the second embodiment configured as described above, the step (S130) of preparing the first cover substrate 120a and the first display layer 130a in FIG. The bank 132 corresponding to the boundary of each of the plurality of first pixels and the at least one organic layer 131 corresponding to each of the plurality of first pixels are formed on the substrate 110b to form the first display layer 130b. Forming a first common electrode 122 corresponding to the plurality of first pixels on the second substrate 121 to provide a first cover substrate 120b and a first cover substrate 120b. And bonding the transistor array substrate 110b to each other. In this case, in the preparing of the first display layer 130b, as illustrated in FIG. 11A, the bank 132 is formed on the transistor array substrate 110b corresponding to the boundary of each of the plurality of first pixels. Thereafter, as shown in FIG. 11B, at least one organic layer 131 is formed corresponding to each of the plurality of first pixels in a portion where the bank 132 on the transistor array substrate 110b is not formed. In the bonding of the first cover substrate 120b and the transistor array substrate 110b, as illustrated in FIG. 11C, the first cover substrate 120b is aligned with the upper portion of the first display layer 120b. Afterwards, the transistor array substrate 110b and the first cover substrate 120b are sealed to prevent oxygen or moisture from being introduced into the predetermined space between the transistor array substrate 110b and the first cover substrate 120b. 1 Attach the cover substrate 120b. In addition, according to the second embodiment, the step (S150) of preparing the second cover substrate 140 and the second display layer 150 in FIG. 4 is similar to that of the first embodiment. ) Forming a second cover substrate by forming a second common electrode 142 corresponding to the plurality of second pixels, and providing a second display layer 150 on the second common electrode 121. And attaching the second display layer 150 to the other surface of the transistor array substrate 110b. At this time, in the step of attaching the second display layer 150 to the other surface of the transistor array substrate 110b, as shown in FIG. 11D, the second display layer 150 is the second cover substrate 140 and the transistor. The second display layer 140 and the transistor array substrate 110b are attached to each other using the adhesive layer AD formed on the second display layer 150 while being aligned to be positioned between the array substrates 110b.

Next, the double-sided display device according to the third and fourth exemplary embodiments of the present invention may include a plurality of first pixels driven on one surface by a liquid crystal display method, and a plurality of second pixels driven on the other surface by an electrophoretic display method. It is made to include. In this case, the plurality of first pixels included in the double-sided display device according to the third embodiment is driven by a reflective liquid crystal display using light incident from the outside, and the plurality of first pixels included in the double-sided display device according to the fourth embodiment. The first pixel is driven by a transmissive liquid crystal display using light supplied from a separately provided backlight unit.

First, the double-sided display device according to the third embodiment will be described.

12 is a cross-sectional view illustrating a double-sided display device according to a third exemplary embodiment of the present invention, and FIGS. 13A to 13D are flowcharts illustrating a process of manufacturing the double-sided display device according to the third exemplary embodiment of the present invention.

The double-sided display device according to the third exemplary embodiment of the present invention includes a transistor array substrate 110c for controlling luminance of each of a plurality of first pixels and a plurality of second pixels, and a first cover substrate corresponding to the plurality of first pixels. And a second cover substrate 140 and a second display layer 150 corresponding to the first display layer 130c and the plurality of second pixels. Here, the first display layer 130c is formed of a liquid crystal layer including a liquid crystal cell that is twisted in accordance with an electric field and selectively scatters light.

In detail, the transistor array substrate 110c is formed on the first substrate 111 and the first substrate 111 in the form of a metal thin film in a mesh pattern to polarize light incident from the outside by λ / 2 to polarize the first display layer. A plurality of first transistors TFT1, a plurality of second transistors TFT2, and a plurality of first transistors TFT1 formed on the polarizing reflection layer 117a and the reflective reflection layer 117a reflecting toward 130c are respectively connected. The first common electrode CX and the plurality of second pixel electrodes PX1 that are alternately formed with the plurality of first pixel electrodes PX1 and to which a common electrode corresponding to the plurality of first pixels is applied A plurality of second pixel electrodes PX2 connected to the transistor TFT2, a protective layer 114 formed on the plurality of first transistors TFT1, and a plurality of second transistors TFT2, and a plurality of firsts, respectively. The color filter layer CF is formed on the passivation layer 116 including the pixel electrode PX1 and the first common electrode CX. Achieved. In this case, the polarization reflecting layer 117a is formed on the first substrate 111, and the plurality of first transistors TFT1 and the plurality of second transistors TFT2 are formed on the polarization reflecting layer 117a and the polarization reflecting layer 117a. It is formed insulated from. That is, although not specifically illustrated in FIG. 12, an insulation layer (not shown) is formed on the polarization reflection layer 117a, and the plurality of first transistors TFT1 and the plurality of second transistors are formed on the insulation layer (not shown). Each gate electrode G is formed, and a gate insulating film 112 is formed on an insulating layer (not shown) including the gate electrode G. The first pixel electrode PX1 and the first common electrode CX are alternately formed on the protective layer 114 to correspond to pixel openings of each of the plurality of first pixels. In addition, the plurality of second contact holes 116 are formed on the first substrate 111, the polarization reflection layer 117a, and the gate insulating layer 112. In addition, the color filter layer CF is formed on the passivation layer 114 to correspond to the pixel area of each of the first pixels, and is positioned to surround the first pixel electrode PX1 and the common electrode CX. In this case, the color filter layer CF may include a dye or a pigment that transmits only light of a specific wavelength region in light, and may correspond to any one of R, G, and B colors. Except for this point, since the transistor array substrate 110c according to the third embodiment of the present invention is the same as the description of the transistor array substrate 110 illustrated in FIG. 2, descriptions thereof will be omitted below. Shall be.

The first cover substrate 120c according to the third embodiment includes the second substrate 121. In this case, although not specifically illustrated in FIG. 12, the first cover substrate 120c may be formed on one surface of the second substrate 121 to correspond to an outer periphery of the pixel opening of each of the plurality of first pixels. It may comprise a black matrix layer (not shown) to prevent light leakage phenomenon. In addition, the first cover substrate 120c is formed on the back surface of the second substrate 121 that is not opposed to the transistor array substrate 110c in the form of a metal thin film in a mesh pattern, and polarizes light traveling from the liquid crystal layer to the outside. It further comprises a polarizing layer 117b.

In addition, the first display layer 130c is injected between the transistor array substrate 110c and the first cover substrate 120c, and includes a liquid crystal cell in which a cell direction is adjusted according to an electric field to selectively scatter light. Is done. In this case, the liquid crystal cell of the first display layer 130c has a cell direction adjusted according to an electric field formed between the first pixel electrode PX1 and the first common electrode CX for each first pixel, and is incident from the outside. The light reflected by the polarizing reflector 117a and polarized by [lambda] / 2 is directed toward the polarizing plate 117b in the direction scattered or polarized by the liquid crystal cell. In addition, the polarizing plate 117b transmits the light traveling in the direction polarized by the polarizing reflector 117a, that is, the light that is not scattered to the outside, and transmits only the light scattered by the liquid crystal cell to the outside. Accordingly, the luminance of each of the first pixels is adjusted by the pixel aperture ratio corresponding to the electric field formed between the first pixel electrode PX1 and the first common electrode CX.

In addition, as the reflective polarizer 117a and the polarizer 117b are made of a metal thin film having a mesh pattern, the reflective polarizer 117a is formed by high heat in the process of forming the semiconductor layer 113, as compared with the plastic having low heat resistance. Deformation of the shape of the polarizing plate 117b can be prevented.

In addition, according to the third embodiment, the second cover substrate 140 includes a third substrate 141 and a second common electrode 142 corresponding to the plurality of second pixels. In addition, the second display layer 150 includes a plurality of microcapsules spread therein and an electron ink layer including a binder made of a polymer filled between the plurality of microcapsules. Each microcapsule has polarities opposite to each other. It consists of the form which sealed the solvent in which the two types of pigment particle which it has disperse | distributed. Here, the second cover substrate 140 and the second display layer 150 according to the third embodiment may include the second cover substrate 140 and the second display layer 150 according to the first embodiment shown in FIG. 8. Since the description is the same as), duplicate descriptions will be omitted below.

According to the method of manufacturing the double-sided display device according to the third exemplary embodiment configured as described above, preparing the transistor array substrate in FIG. 6 (S120) may include forming a polarized light reflecting layer before forming the gate electrode (G). And forming the color filter layer CF on the passivation layer 114 corresponding to the pixel region after the forming of the plurality of first pixel electrodes PX1. In the forming of the plurality of first pixel electrodes PX1, a first common electrode CX corresponding to the plurality of first pixels is further formed on the passivation layer 114. That is, the first common electrode CX and the plurality of first pixel electrodes PX1 are simultaneously formed using the same mask. In the forming of the polarization reflection layer 117a, as shown in FIG. 13A, a plurality of second pixel electrodes PX2 and the first substrate 111 are sequentially stacked on the transfer substrate CSub. The reflective polarizer 117a is formed on the first substrate 111 in the form of a metal thin film having a mesh pattern. In this case, the reflective polarizer 117a may be made of a metal having high reflectance such as aluminum or silver. The method may further include forming an insulating layer (not shown) on the lower polarization layer 117c to electrically protect the plurality of first transistors TFT1 and the plurality of second transistors TFT2. .

Further, according to the third embodiment, the step (S130) of preparing the first cover substrate and the first display layer in FIG. 4 includes a first substrate including a third substrate 121 made of a material having transparency and flexibility. Providing a cover substrate 120c, aligning the first cover substrate 120c to face one surface of the transistor array substrate 110c, and forming a liquid crystal between the transistor array substrate 110c and the first cover substrate 120c. Implanting a layer to form the first display layer 130c, and bonding the transistor array substrate 110c and the first cover substrate 120c to each other. In this case, the preparing of the first cover substrate 120c may include forming a polarizing plate 117c on a rear surface of the second substrate (not shown) that does not face the transistor array substrate 110c. In the step of aligning the first cover substrate 120c, as shown in FIG. 13B, the first cover substrate 120c is aligned to face one surface of the transistor array substrate 110c. Thereafter, as illustrated in FIG. 13C, a liquid crystal layer is injected between the transistor array substrate 110c and the first cover substrate 120c to prepare a first display layer 130c, and the transistor array substrate 110c and the first display layer 130c. 1 Attach the cover substrate 120c.

In addition, according to the third exemplary embodiment, in the preparing of the second cover substrate 140 and the second display layer 150 in FIG. 4 (S150), the plurality of second pixels on the third substrate 141 may be provided. Forming a second common electrode 142 corresponding to the second cover substrate 140, preparing a second display layer 150 on the second common electrode 121, and forming a transistor array substrate ( Attaching the second display layer 150 to the other surface of the 110c. At this time, in the step of attaching the second display layer 150 to the other surface of the transistor array substrate 110c, as shown in FIG. 13D, the second display layer 150 is the second cover substrate 140 and the transistor. The second display layer 140 and the transistor array substrate 110c are attached to each other using the adhesive layer AD formed on the second display layer 150 while being aligned to be positioned between the array substrates 110c.

Next, the double-sided display device according to the fourth embodiment will be described.

14 is a cross-sectional view illustrating a double-sided display device according to a fourth exemplary embodiment of the present invention, and FIGS. 15A to 15D are flowcharts illustrating a process of manufacturing the double-sided display device according to the fourth exemplary embodiment of the present invention.

The double-sided display device according to the fourth exemplary embodiment of the present invention includes a transistor array substrate 110d for controlling luminance of each of a plurality of first pixels and a plurality of second pixels, and a first cover substrate corresponding to the plurality of first pixels. And a second cover substrate 140 and a second display layer 150 corresponding to the first display layer 130c and the plurality of second pixels. In the double-sided display device according to the fourth embodiment, the first cover substrate 120c, the first display layer 130c, the second cover substrate 140, and the second display layer 150 are illustrated in FIG. 12. Since it is the same as in the double-sided display device according to the third embodiment, a description thereof will be omitted below.

According to the fourth embodiment, the transistor array substrate 110d is formed on the first substrate 111 and the first substrate 111 to supply light to the first display layer 130c and the mesh. A plurality of first transistors formed on the lower polarizing layer 117c and the lower polarizing layer 117c which are formed in a patterned metal thin film and polarize light traveling from the backlight unit 160 to the first display layer 130c. A plurality of first pixel electrodes PX1 and a plurality of first pixel electrodes PX1 connected to the TFT1, the plurality of second transistors TFT2, and the plurality of first transistors TFT1, respectively, A first common electrode CX to which a common electrode corresponding to the first pixel of the pixel is applied, a plurality of second pixel electrodes PX2 connected to the plurality of second transistors TFT2, and a plurality of first transistors TFT1, respectively And a first common electric field with the passivation layer 114 and the plurality of first pixel electrodes PX1 formed on the plurality of second transistors TFT2. Comprises a color filter layer (CF) is formed on an upper protective layer (116) including (CX). Here, the backlight unit 160 is formed on at least one side edge of one surface of the first substrate 111 and is formed on one surface of the first substrate 111 and the light source 161 to supply light. And a waveguide 162 for transmitting the light supplied from the light source to the liquid crystal layer provided as the first display layer 130c. The lower polarization layer 117c is formed on the waveguide 162, and the gate electrode G is insulated from the lower polarization layer 117c on the lower polarization layer 117c. That is, although not specifically illustrated in FIG. 14, an insulating layer (not shown) is formed on the lower polarization layer 117c, and a plurality of first transistors TFT1 and a plurality of second transistors are disposed on the insulating layer (not shown). A gate electrode G of each of the transistors TFT2 is formed, and a gate insulating film 112 is formed on an insulating layer (not shown) including the gate electrode G. In addition, the plurality of second contact holes 116 are formed on the first substrate 111, the waveguide 162, the lower polarization layer 117c, and the gate insulating layer 112. In addition, the color filter layer CF is formed on the passivation layer 114 to correspond to the pixel area of each of the first pixels, and is positioned to surround the first pixel electrode PX1 and the common electrode CX. In this case, the color filter layer CF may include a dye or a pigment that transmits only light of a specific wavelength region in light, and may correspond to any one of R, G, and B colors. Except for this, the transistor array substrate 110d according to the fourth embodiment of the present invention is the same as the description of the transistor array substrate 110c according to the third embodiment shown in FIG. 12. Duplicate explanations will be omitted.

According to the method of manufacturing the double-sided display device according to the fourth embodiment configured as described above, preparing the transistor array substrate (S120) in FIG. 6 may include a backlight unit before forming the gate electrode (G). And forming the polarization reflection layer 117a, and after forming the plurality of first pixel electrodes PX1, the color corresponding to the pixel area on the protective layer 114. The method may further include forming the filter layer CF, and in the forming of the plurality of first pixel electrodes PX1, the first common electrode CX corresponding to the plurality of first pixels on the passivation layer 114. This is further formed. That is, the first common electrode CX and the plurality of first pixel electrodes PX1 are simultaneously formed using the same mask.

The forming of the backlight unit may include forming a light source 161 on at least one edge of one surface of the first substrate 111 and forming a waveguide 162 on one surface of the first substrate 111. It includes. Subsequently, in the step of forming the polarization reflection layer 117a, as shown in FIG. 15A, the lower polarization layer 117c is formed in the form of a metal thin film having a mesh pattern on the waveguide 162. The method may further include forming an insulating layer (not shown) on the lower polarization layer 117c to electrically protect the plurality of first transistors TFT1 and the plurality of second transistors TFT2. .

According to the fourth embodiment, the preparing of the first cover substrate and the first display layer (S130) in FIG. 4 includes a first cover substrate including a third substrate 121 made of a material having transparency and flexibility. Preparing a 120c, arranging the first cover substrate 120c to face one surface of the transistor array substrate 110d, and forming a liquid crystal layer between the transistor array substrate 110d and the first cover substrate 120c. Implanting the first display layer 130c and bonding the transistor array substrate 110d and the first cover substrate 120c to each other. In this case, the preparing of the first cover substrate 120c may include forming the upper polarizing plate 117c on the rear surface of the second substrate (not shown) that does not face the transistor array substrate 110d. In the step of aligning the first cover substrate 120c, as shown in FIG. 15B, the first cover substrate 120c is aligned to face one surface of the transistor array substrate 110d. Thereafter, as illustrated in FIG. 15C, a liquid crystal layer is injected between the transistor array substrate 110d and the first cover substrate 120c to prepare the first display layer 130c, and the transistor array substrate 110d and the first display layer 130c are formed. 1 Attach the cover substrate 120c.

In addition, according to the fourth exemplary embodiment, in the preparing of the second cover substrate 140 and the second display layer 150 in FIG. 4 (S150), the plurality of second pixels on the third substrate 141 may be provided. Forming a second common electrode 142 corresponding to the second cover substrate 140, preparing a second display layer 150 on the second common electrode 121, and forming a transistor array substrate ( Attaching the second display layer 150 to the other surface of 110d). At this time, in the step of attaching the second display layer 150 to the other surface of the transistor array substrate 110d, as shown in FIG. 15D, the second display layer 150 is the second cover substrate 140 and the transistor. The second display layer 140 and the transistor array substrate 110d are attached to each other using the adhesive layer AD formed on the second display layer 150 while being aligned to be positioned between the array substrates 110d.

As described above, the double-sided display device according to the exemplary embodiment of the present invention includes a plurality of first pixels formed on one surface and a plurality of second pixels formed on the other surface, and includes a plurality of first pixels and a plurality of first pixels. A plurality of first transistors TFT1 and a plurality of second transistors TFT2 respectively controlling two pixels are included to display different image information on both surfaces. In this case, the plurality of first transistors TFT1 and the plurality of second transistors TFT2 are formed on one surface of the same substrate 111, and the plurality of first transistors applying pixel voltages corresponding to each of the plurality of first pixels. The pixel electrode PX1 is formed on the top surface of the substrate 111, and the plurality of second pixel electrodes PX2 that apply pixel voltages corresponding to each of the plurality of second pixels are formed on the back surface of the substrate. A transistor array substrate corresponding to both the first pixel and the plurality of second pixels may be provided. Accordingly, at least one substrate can be removed, compared to the prior art having a transistor array substrate corresponding to each of the plurality of first pixels and the plurality of second pixels, thereby reducing thickness and weight. In addition, since a plurality of first transistors TFT1 and a plurality of second transistors TFT2 are simultaneously formed on one substrate 111 and two substrates do not need to be attached, the manufacturing process becomes easier and the manufacturing cost is increased. By this decrease, the yield can be improved. In addition, unlike the prior art in which two transistor array substrates are attached, since the transistor array substrate may be formed using only one flexible substrate, the transistor array substrate may be manufactured to have flexibility, thereby improving practicality.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes may be made without departing from the technical spirit of the present invention.

100: double-sided display device 110: transistor array substrate
111: first substrate TFT1: first transistor (first switching element)
TFT2: second transistor (second switching element)
PX1: first pixel electrode PX2: second pixel electrode
120: first cover substrate 130: first display layer
140: second cover substrate 150: second display layer

Claims (31)

A double-sided display device for displaying image information on both sides by having a first display unit on one side and a second display unit on the other side,
A first substrate;
A plurality of first unit pixels formed on one surface of the first substrate and constituting the first display unit;
A plurality of second unit pixels formed on the other surface of the first substrate and constituting the second display unit;
A plurality of first switching elements formed on the first substrate and respectively corresponding to the plurality of first unit pixels, and formed on the same surface as the plurality of first switching elements and respectively corresponding to the plurality of second unit pixels. An array substrate including a plurality of second switching elements;
A first display layer formed on the first display unit; And
And a second display layer formed on the second display unit. The method of claim 1,
The first display unit further includes a first cover substrate facing one surface of the array substrate,
And the second display unit further comprises a second cover substrate facing the other surface of the array substrate. The method of claim 1,
The first substrate,
A double-sided display device comprising a flexible plastic material that is soluble in a predetermined solvent and has heat resistance. The method of claim 3,
And the first substrate is made of polyimide. The method of claim 1,
Each of the plurality of first switching elements and the plurality of second switching elements,
A gate electrode formed on the first substrate;
A gate insulating layer formed on an entire surface of the first substrate including the gate electrode;
At least a portion of the semiconductor layer overlapping the gate electrode on the gate insulating layer; And
And a thin film transistor including a source electrode and a drain electrode formed on the semiconductor layer and overlapping both sides of the gate electrode. The method of claim 1,
The array substrate,
A plurality of first pixel electrodes connected to the plurality of first switching elements, respectively; And
And a plurality of second pixel electrodes connected to the plurality of second switching elements, respectively. The method of claim 1,
The array substrate,
A protective layer covering a surface of the plurality of first switching elements and the plurality of second switching elements to protect a surface thereof;
A plurality of first pixel electrodes formed on the passivation layer and connected to the plurality of first switching elements through a plurality of first contact holes respectively formed on the passivation layer and corresponding to the plurality of first unit pixels, respectively. ; And
And a plurality of second pixel electrodes formed on a rear surface of the first substrate and connected to the plurality of second switching elements through a plurality of second contact holes respectively corresponding to the second unit pixels. Duplex Display. The method of claim 1,
And the first and second display layers each include an electronic ink layer. The method of claim 8,
The first display layer further includes a first common electrode configured to apply an electric field to the electron ink layer of the first display layer together with the first pixel electrode.
And the second display layer further includes a second common electrode configured to apply an electric field to the electron ink layer of the second display layer together with the second pixel electrode. The method of claim 7, wherein
The first display layer includes an organic light emitting layer,
And the second display layer comprises an electron ink layer. The method of claim 10,
The first display layer further includes a bank formed corresponding to each boundary of each of the plurality of first unit pixels, and a first cover substrate facing one surface of the array substrate.
The organic light emitting layer is at least one organic layer formed corresponding to each of the plurality of first unit pixels,
And the first cover substrate includes a second substrate having transparency and flexibility and a common electrode formed on one surface of the second substrate. The method of claim 1,
The first display layer is formed of a liquid crystal layer including a liquid crystal cell that selectively scatters light according to an electric field,
And the second display layer comprises an electron ink layer. The method of claim 12,
The array substrate,
And a second common electrode corresponding to the plurality of first unit pixels and alternately formed on the passivation layer with the first pixel electrode. The method of claim 12,
The first display unit further includes a second substrate having transparency and flexibility, and a polarizing layer formed on the second substrate in the form of a metal thin film in a mesh pattern and polarizing light traveling from the liquid crystal layer to the outside.
And the array substrate is formed in the form of a metal pattern of a mesh pattern on the first substrate, and further comprises a polarization reflection layer that polarizes the light incident from the outside and reflects the light to the liquid crystal layer. The method of claim 12,
The first display unit further includes a second substrate having transparency and flexibility, and a first polarization layer formed on the second substrate in the form of a metal thin film in a mesh pattern, and polarizing light traveling from the liquid crystal layer to the outside.
The array substrate,
A backlight including a light source formed on at least one side edge of one surface of the first substrate to supply light and a waveguide formed on one surface of the first substrate to transfer light supplied from the light source to the liquid crystal layer; unit; And a second polarization layer formed on the waveguide in the form of a metal thin film having a mesh pattern to polarize light incident from the waveguide into the liquid crystal layer. 1. A method of manufacturing a double-side display device for displaying image information on both surfaces, including a plurality of first pixels formed on one surface and a plurality of second pixels formed on the other surface.
Forming a plurality of first pixel electrodes respectively corresponding to the plurality of second pixels on a transfer substrate;
Forming a flexible first substrate on a portion of the transfer substrate including the plurality of first pixel electrodes;
Providing a transistor array substrate including the first substrate, a plurality of first transistors respectively corresponding to the plurality of first pixels, and a plurality of second transistors respectively corresponding to the plurality of second pixels;
Providing a first display layer corresponding to the plurality of first pixels on one surface of the transistor array substrate;
Removing the transfer substrate from the transistor array substrate by separating the first substrate and the transfer substrate; And
And providing a second display layer on the other surface of the transistor array substrate, the second display layer corresponding to the plurality of second pixels. The method of claim 16,
Forming the first substrate,
And coating a flexible plastic material that is soluble in a predetermined solvent and has heat resistance on the transfer substrate. The method of claim 17,
And forming the first substrate, wherein the plastic material is polyimide. The method of claim 16,
Preparing the transistor array substrate,
Forming a gate electrode on the first substrate corresponding to each of the plurality of first transistors and the plurality of second transistors;
Forming a gate insulating layer on an entire surface of the first substrate including the gate electrode;
Forming a semiconductor layer corresponding to each of the plurality of first transistors and the plurality of second transistors, the semiconductor layer at least partially overlapping the gate electrode on the gate insulating layer;
Forming a plurality of first contact holes respectively corresponding to partial regions of the plurality of first pixel electrodes;
Forming a source electrode and a drain electrode on the semiconductor layer, respectively corresponding to both sides of the gate electrode, corresponding to each of the plurality of first transistors and the plurality of second transistors; And
And forming a protective layer on an entire surface of the gate insulating layer including the semiconductor layer, the source electrode, and the drain electrode. 20. The method of claim 19,
In the forming of the source electrode and the drain electrode, the plurality of second transistors are connected to the plurality of first pixel electrodes through the plurality of first contact holes, respectively. The method of claim 20,
Preparing the transistor array substrate,
Forming a plurality of second contact holes respectively corresponding to the plurality of first transistors on the protective layer; And
And forming a plurality of second pixel electrodes respectively connected to the plurality of first transistors through the plurality of second contact holes on the passivation layer. The method of claim 20,
Preparing the second display layer may include
Providing a first cover substrate by forming a first common electrode corresponding to the plurality of second pixels on one surface of a second support substrate made of a material having transparency and flexibility;
Forming the second display layer on the first common electrode with an electron ink layer including microcapsules formed in a form in which a solvent in which two kinds of pigment particles having opposite polarities are dispersed is sealed; And
And attaching the second display layer to another surface of the transistor array substrate such that the second display layer is positioned between the plurality of second pixel electrodes and the first common electrode. Method of manufacturing the device. The method of claim 22,
Preparing the first display layer may include
Preparing a second cover substrate by forming a second common electrode corresponding to the plurality of first pixels on one surface of a third substrate made of a material having transparency and flexibility;
Forming the first display layer on the second common electrode by using an electron ink layer including a microcapsule in which a solvent in which two kinds of pigment particles having opposite polarities are dispersed is sealed; And
And attaching the first display layer to one surface of the transistor array substrate such that the first display layer is positioned between the plurality of first pixel electrodes and the second common electrode. Manufacturing method. The method of claim 23, wherein
The preparing of the transistor array substrate may further include forming a planar upper passivation layer on the plurality of second transistors before forming the plurality of second contact holes.
And in the forming of the plurality of second pixel electrodes, the plurality of second pixel electrodes is formed on the upper passivation layer. The method of claim 22,
Preparing the first display layer may include
Forming the first display layer on the transistor array substrate with a bank corresponding to a boundary of each of the plurality of first pixels and at least one organic layer corresponding to each of the plurality of first pixels;
Providing a second cover substrate by forming a second common electrode corresponding to the plurality of first pixels on one surface of a third substrate made of a material having transparency and flexibility; And
Bonding the second cover substrate to the transistor array substrate such that a first display layer is positioned between the second common electrode and the plurality of first pixel electrodes. . The method of claim 22,
Preparing the first display layer may include
Providing a second cover substrate comprising a third substrate made of a material having transparency and flexibility;
Aligning the second cover substrate to one surface of the transistor array substrate;
Forming a first display layer by injecting a liquid crystal layer including a liquid crystal cell in which a twisted direction is adjusted according to an electric field between the transistor array substrate and the first cover substrate to selectively scatter light; And
And bonding the transistor array substrate and the second cover substrate to each other. The method of claim 26,
The preparing of the transistor array substrate may further include forming a plurality of second common electrodes corresponding to the plurality of first pixels and alternately with the plurality of second pixel electrodes on the passivation layer. A method of manufacturing a double-sided display device characterized in that. The method of claim 26,
The preparing of the transistor array substrate may include forming a polarization reflection layer between the first substrate and the gate insulation layer to polarize light incident from the outside and reflect the light to the liquid crystal layer before forming the gate electrode. Further comprising:
The preparing of the first display layer may further include forming a polarization layer on the third substrate to polarize light traveling from the liquid crystal layer to the outside. The method of claim 28,
In the forming of the polarized light reflecting layer and the forming of the polarizing layer,
The polarization reflection layer and the polarization layer is a method of manufacturing a double-side display device, characterized in that each formed in the form of a metal film of a mesh pattern. The method of claim 26,
The step of preparing the transistor array substrate, before forming the gate electrode,
Forming a light source for supplying light to at least one side edge on one surface of the first substrate;
Forming a waveguide for transmitting the light supplied from the light source to the liquid crystal layer on one surface of the first substrate; And
Forming a first polarization layer between the waveguide and the gate insulating layer to polarize light incident from the waveguide into the liquid crystal layer;
The preparing of the first display layer may further include forming a second polarization layer on the third substrate to polarize light traveling from the liquid crystal layer to the outside. Way. The method of claim 30,
In the forming of the first polarizing layer and the forming of the second polarizing layer,
The first polarization layer and the second polarization layer is a method of manufacturing a double-side display device, characterized in that each formed in the form of a metal thin film of a mesh pattern.

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